Abstract: A pressurized ball testing device for determining the relative pressure of tennis balls or other inflated balls whose internal pressure cannot be directly measured comprises a housing having two half shells, attached along a common axis so that the two half shells are movable along the central axis relative to each other. The interior of each half shell has a ball support centered on the central axis. The ball to be measured is placed between the two ball supports so that when the two half shells are pressed together, the ball is simultaneously compressed and held in place. The pressures are relative to a new ball or reference ball, allowing the balls to be sorted for suitability of play. Two methods of measurement are described, one using constant force and the other using constant displacement. In either case the ball to be tested is squeezed from opposite sides by finger-like protrusions to enhance the displacement of the side of the ball for a given force.

Abstract: An adaptive process control system selectively controls vibrations in a given medium in real time. Unwanted vibrations present at a point being monitored in a given medium are sensed, and the system generates an appropriate offsetting vibration that is applied to the medium at a convenient location, which may be remote from the monitored point. The system includes a vibration sensor, such as one or more accelerometers, that sense both input and output vibrations present within the medium; at least one vibration generator, such as an electromagnetic shaker, that generates appropriate offsetting vibrations that are applied to the medium at one or more appropriate locations; and a neural network controller that controls the vibration generator(s) so as to force the sensed vibration at the monitored point(s) to a desired level. The adaptive vibration cancellation provided by the invention takes place in real time, and without the need to process time-consuming complex mathematical algorithms.

Abstract: A method and a system for reducing the acoustic levels of internal and external sound fields generated by gas turbine engines has several actuators to generate sound, several sensors to measure the acoustic levels, and one or more controllers, The controllers are adaptive self-learning neural networks that control the actuators to generate sound in order to effect the reduction of the internal and external sound field as measured by the Sensors.

Abstract: An adaptive process control system selectively controls vibrations in a given medium in real time. Unwanted vibrations present at a point being monitored in a given medium are sensed, and the system generates an appropriate offsetting vibration that is applied to the medium at a convenient location, which may be remote from the monitored point. The system includes a vibration sensor, such as one or more accelerometers, that sense both input and output vibrations present within the medium; at least one vibration generator, such as an electromagnetic shaker, that generates appropriate offsetting vibrations that are applied to the medium at one or more appropriate locations; and a neural network controller that controls the vibration generator(s) so as to force the sensed vibration at the monitored point(s) to a desired level. The adaptive vibration cancellation provided by the invention takes place in real time, and without the need to process time-consuming complex mathematical algorithms.